Once the capture volume is calibrated and all markers are placed, you are now ready to capture Takes. In this page, we will cover key concepts and tips that are important for the recording pipeline. For real-time tracking applications, you can skip this page and read through the Data Streaming page.
There are two different modes in Motive: Live mode and Edit mode. You can toggle between two modes from the Control Deck or by using the (Shift + ~) hotkey.
Live Mode
The Live mode is mainly used when recording new Takes or when streaming a live capture. In this mode, all of the cameras are continuously capturing 2D images and reconstructing the detected reflections into 3D data in real-time.
Edit Mode
The Edit Mode is used for playback of captured Take files. In this mode, you can playback, or stream, recorded data. Also, captured Takes can be post-processed by fixing mislabeling errors or interpolating the occluded trajectories if needed.
Tip: Prime series cameras will illuminate in blue when in live mode, in green when recording, and turned-off in edit mode. See more at Camera Status Indicators.
Recording in Motive is triggered from the Control Deck when in the Live mode, and the recorded data
In Motive, capture recording is controlled from the Control Deck. In the Live mode, new Take** name** can be assigned in the name box or you can just simply start the recording and let Motive automatically generate new names on the fly. You can also create empty Takes in the Data Management pane for a better organization. To start the capture, select Live mode and click the recording button (red). In the control deck, record time and frames are displayed in (Hour:Minute:Second:Frames).
Tip: For Skeleton tracking, always start and end the capture with a T-pose or A-pose, so that the Skeleton assets can be redefined from the recorded data as well.
Tip: Efficient ways of managing Takes
Always start by creating session folders for organizing related Takes. (e.g. name of the tracked subject).
Plan ahead and create a list of captures in a text file or a spreadsheet, and you can create empty takes by copying and pasting the list into the Data Management pane (e.g. walk, jog, run, jump).
Once pasted, empty Takes with the corresponding names will be imported.
Select one of the empty takes and start recording. The capture will be saved with the corresponding name.
If the capture was unsuccessful, simply record the same Take again and another one will be recorded with a incremented suffix added at the end of the given Take name (e.g. walk_001, walk_002, walk_003). The suffix format is defined in the Application Settings.
When captured successfully, select another empty Take in the list and capture the next one.
When a capture is first recorded, both 2D data and real-time reconstructed 3D data is saved onto the Take. For more details on each data type, refer to the Data Types page.
2D data: The recorded Take file includes just the 2D object images from each camera.
3D data: The recorded Take file also includes reconstructed 3D marker data in addition to 2D data.
Throughout capture, you might recognize that there are different types of markers that appear in the 3D perspective view. In order to correctly interpret the tracking data, it is important to understand the differences between these markers. There are three different displayed marker types: markers, Rigid Body markers, and bone (or Skeleton) markers.
Marker data, labeled or unlabeled, represent the 3D positions of markers. These markers do not present Rigid Body or Skeleton solver calculations but locate the actual marker position calculated from the camera data. These markers are represented as a solid sphere in the viewport. By default, unlabeled markers are colored in white, and labeled markers will have colors that reflect the color setting in the Rigid Body or the corresponding bone.
Labeled Marker Colors:
Colors of the unlabeled markers can be changed from the Application Settings.
Colors of the Rigid Body labeled markers can be changed from the properties of the corresponding asset.
Colors of the markers can be changed from the Constraints XML file if needed.
Rigid body markers or bone markers are expected marker positions. They appear as transparent spheres within a rigid body, or a skeleton, and they reflect the position that the rigid body or skeleton solver expects to find a corresponding reconstructed marker. Calculating these positions assumes that the marker is fixed on a rigid segment that doesn’t deform over the course of capture. When the rigid body solver or skeleton solver are correctly tracking reconstructed markers, both marker reconstructions, and expected marker positions will have similar position values and will closely align in the viewport.
When creating rigid bodies, their associated markers will appear as a network of lines between markers. Skeleton marker expected positions would be located next to body segments, or bones. Please see Figure 2. If the marker placement is distorted during capture, the actual marker position will deviate from the expected position. Eventually, the marker may become unlabeled. Figure 1. shows how actual and expected marker positions could align or deviate from each other. Due to the nature of marker-based mocap systems, labeling errors may occur during capture. Thus, understanding each marker type in Motive is very important for correct interpretation of the data.
Read through the Labeling page for more information on marker labels.
This page explains different types of captured data in Motive. Understanding these types is essential in order to fully utilize the data-processing pipelines in Motive.
There are three different types of data: 2D data, 3D data, and Solved data. Each type of data will be covered in detail throughout this page, but basically, 2D Data is the captured camera frame data, 3D Data is the reconstructed 3-dimensional marker data, and Solved data is the calculated positions and orientations of Rigid Bodies and Skeleton segments.
Motive saves tracking data into a Take file (TAK extension), and when a capture is initially recorded, all of the 2D data, real-time reconstructed 3D data, and solved data are saved onto a Take file. Recorded 3D data can be post-processed further in Edit mode, and when needed, a new set of 3D data can be re-obtained from saved 2D data by performing the reconstruction pipelines. From the 3D data, Solved data can be derived.
Available data types are listed on the Data pane. When you open up a Take in Edit mode, the loaded data type will be highlighted at the top-left corner of the 3D viewport. If available, 3D Data will be loaded first by default, and the 2D data can be accessed by entering the 2D Mode from the Data pane.
2D data is the foundation of motion capture data. It mainly includes the 2D frames captured by each camera in a system.
Images in recorded 2D data depend on the image processing mode, also called the video type, of each camera that was selected at the time of the capture. Cameras that were set to reference modes (MJPEG grayscale images) record reference videos, and cameras that were set to tracking modes (object, precision, segment) record 2D object images which can be used in the reconstruction process. The latter 2D object data contains information on x and y centroid positions of the captured reflections as well as their corresponding sizes (in pixels) and roundness, as shown in the below images.
Using the 2D object data along with the camera calibration information, 3D data is computed. Extraneous reflections that fail to satisfy the 2D object filter parameters (defined under application settings) get filtered out, and only the remaining reflections are processed. The process of converting 2D centroid locations into 3D coordinates is called Reconstruction, which will be covered in the later section of this page.
3D data can be reconstructed either in real-time or in post-capture. For real-time capture, Motive processes captured 2D images on a per-frame basis and streams the 3D data into external pipelines with extremely low processing latency. For recorded captures, the saved 2D data can be used to create a fresh set of 3D data through post-processing reconstruction, and any existing 3D data will be overwritten with the newly reconstructed data.
Contains 2D frames, or 2D object information captured by each camera in a system. 2D data can be monitored from the Camera Preview pane.
Recorded 2D data can be reconstructed and auto-labeled to derive the 3D data.
3D tracking data is not computed yet. The tracking data can be exported only after reconstructing the 3D data.
In playback of recorded 2D data, 3D data will be Live-reconstructed into 3D data and reported in the 3D viewport.
3D data contains 3D coordinates of reconstructed markers. 3D markers get reconstructed from 2D data and shows up the perspective view. Each of their trajectories can be monitored in the Graph pane. In recorded 3D data, marker labels can be assigned to reconstructed markers either through the auto-labeling process using asset definitions or by manually assigning it. From these labeled markers, Motive solves the position and orientation of Rigid Bodies and Skeletons.
Recorded 3D data is editable. Each frame of the trajectory can be deleted or modified. The post-processing edit tools can be used to interpolate the missing trajectory gaps or apply the smoothing, and the labeling tools can be used to assign or reassign the marker labels.
Lastly, from a recorded 3D data, its tracking data can be exported into various file formats — CSV, C3D, FBX, and more.
Reconstructed 3D marker positions.
Marker labels can be assigned.
Assets are modeled and the tracking information is available.
Edit tools can be used to fill the trajectory gaps.
Solved data is positional and rotational, 6 degrees of freedom (DoF), tracking data of Rigid Bodies and Skeletons. This data is stored when a TAK is first captured, and it can be removed or recalculated from recorded 3D data. Solved data is fully calculated on all of the recorded frames and if it exists, the real-time Rigid Body and Skeleton solvers do not run during playback. This reduces the amount of processing needed for playback and improves performance.
Record Solved Data
In the Assets pane, right-click on a selected asset(s) and click Record Solved Data. Assets that contain solved data will be indicated under the solved column.
In the Data Management pane, right-click on a Take and click Solve All Assets to produce solved data for all of the associated assets. Takes that contain solved data will be indicated under the solved column.
Recorded 2D data, audio data, and reference videos can be deleted from a Take file. To do this, open the Data pane, right-click on a recorded Take(s), and click the Delete 2D Data from the context menu. Then, a dialogue window will pop-up, asking which types of data to delete. After removing the data, a backup file will be archived into a separate folder.
Deleting 2D data will significantly reduce the size of the Take file. You may want to delete recorded 2D data when there is already a final version of reconstructed 3D data recorded in a Take and the 2D data is no longer needed. However, be aware that deleting 2D data removes the most fundamental data from the Take file. After 2D data has been deleted, the action cannot be reverted, and without 2D data, 3D data cannot be reconstructed again.
Recorded 3D data can be deleted from the context menu in the Data pane. To delete 3D data, right-click on selected Takes and click Delete 3D data, and all reconstructed 3D information will be removed from the Take. When you delete the 3D data, all edits and labeling will be deleted as well. Again, a new 3D data can always be reacquired by reconstructing and auto-labeling the Take from 2D data.
Deleting 3D data for a single _Take_
When frame range is not selected, it will delete 3D data from the entire frame. When a frame range is selected from the Timeline Editor, this will delete 3D data in the selected ranges only.
Deleting 3D data for multiple _Takes_
When multiple Takes are selected from the Data pane, deleting 3D data will remove 3D data from all of the selected Takes. This will remove 3D data from the entire frame ranges.
When a Rigid Body or Skeleton exists in a Take, Solved data can be recorded. From the Assets pane, right-click one or more asset and select Solve from the context menu to calculate the solved data. To delete, simply click Remove Solve.
Assigned marker labels can be deleted from the context menu in the Data pane. The Delete Marker Labels feature removes all marker labels from the 3D data of selected Takes. All markers will become unlabeled.
Deleting labels for a single _Take_
When no frame range is selected, it will unlabel all markers from all Takes. When a frame range is selected from the Timeline Editor, this will unlabel markers in the selected ranges only.
Deleting labels for multiple _Takes_
Even when a frame range is selected from the timeline, it will unlabel all markers from all frame ranges of the selected Takes.
In Motive, all of the recorded capture files are managed through the Data pane. Each capture will be saved in a Take (TAK) file, which can be played back in the Edit mode later. Related Take files can be grouped within session folders. Simply create a new folder in the desired directory and load the folder onto the Data pane. Currently selected session folder is indicated with the flag symbol (), and all newly recorded Takes will be saved in this folder.
